Mechanistic Biology 225 



realism. We shall have to discuss in this paper the question of 

 whether this has been or is justified, and to see whether religion 

 and the other realms of human spiritual experience do indeed con- 

 flict absolutely with mechanism in biology. The historical alterna- 

 tive to mechanism is vitalism, and we shall have to examine that 

 theory as critically as the mechanistic one. We shall have to see 

 whether McDougall's statement, that vitalism is a form of animism 

 characterised by its neglect of the psychophysical problem, is justi- 

 fied. And we shall discuss a position which seems to fit in with 

 the evidence better than the classical ones and to point the way to a 

 synoptic outlook. 



2. The Mechanistic Theory of Life in History 



The mechanistic theory of life is not new. Its history as a 

 theory goes back as far as the first speculations on the nature of life 

 and the universe. But it existed only as a theory, which remained 

 a possible opinion and nothing more, until the sciences of physics 

 and chemistry had had time to discard their embryonic wrappings 

 of pseudo-science. Once natural science was clearly founded on 

 such fundamental hypotheses as the belief in the uniformity of 

 n^ure and such orientations of mind as that which dealt witchcraft 

 its death-blow, then the field was clear for the attempt to see 

 whether living beings would indeed conform to the principles of a 

 mechanistic physiology. In 1527 Paracelsus von Hohenheim, 

 lecturing at Basel, gave biochemistry its charter when he said : 

 " The Body is a conglomeration of chemical matters ; when these 

 are deranged, illness results, and nought but chemical medicines 

 may cure the same." From thenceforward an enormous tract 

 yet remained to be covered before true biochemical researches could 

 begin, for alchemy had yet to yield to iatro-chemistry, and that 

 in turn to the surely built chemistry of the present day. But, 

 nevertheless, since the sixteenth century, the mechanistic theory 

 in biology has been able to point to experimental successes in its 

 support, and indeed, from position to position, sometimes slowly 

 and sometimes with greater rapidity, it has marched forward until 

 it has achieved in the last fifty years its most amazing triumphs. 

 The precise degree of validity of these successes we must reserve 

 for discussion later. 



And all through its history it has evoked the condemnation 



Q 



